PHERUSA BICUSPIS. 



AMPHIPODA. 



NATATORU. 



253 



OAMMAlilDES. 



PllEUUSA BICUSPIS. 



Specific character. First two segments of the pleon dorsally produced into 

 teeth, and the posterior margin of the third segment not serrated ; fourth 

 segment deeply sinuated. 



Length ,f^ inch. 



Amitldtlioc h'lcuspis. Kroyer, Griin. Amjjh. p. 45, pi. i. fig. 1. 



Pherusa bicuspis, Milne Edwards, Hist, des Crust, t. iii. p. 38. Spence 



Bate, Cat. Amph. Brit. Mus. p. 144, pi. xxvii. 



fig. 7. 

 Pherusa cirrus. Spence Bate, Cat. Amph. Brit. Mus. p. 143, pi. xxvdi. 



fig. 6. 



The head is anteriorly produced between the supe- 

 rior antennas. The first two segments of the tail have 

 the dorsal surface posteriorly produced into sharp cusps 

 or flat teeth ; the third segment has the postero-lateral 

 margin smooth — a circumstance which ofiers a ready 

 point of distinction between this species and Atylus 

 hispinosus. The eyes assume a little of the kidney- 



